Not being put to optimum use means an entire property or portion thereof, with or without improvements, which -
(a) Even though used for current program purposes, the nature, value, or location of the property is such that it could be utilized for a different and significantly higher and better purpose; or
(b) The costs of occupying are substantially higher than other suitable properties that could be made available through transfer, purchase, or lease with total net savings to the Government, after considering property values, costs of moving, occupancy, operational efficiency, environmental effects, regional planning, and employee morale.